<template>
  <div>
    <div class="goods">
      <!--左侧list-->
      <div class="menu-wrapper" ref="menuWrapper">
        <ul>
          <!--当currentIndex与index相等的时候，设置高亮-->
          <li class="menu-item" v-for="(item, index) in goods" :class="{current:currentIndex===index}" @click="clickMenuItem(index,$event)">
            <span class="text border-1px">{{item.name}}</span>
          </li>
        </ul>
      </div>
      <!--右侧-->
      <div class="foods-wrapper" ref="foodsWrapper">
        <ul>
          <!--food-list-hook用于dom操作，获取整体容器的高度-->
          <li class="food-list food-list-hook" v-for="item in goods">
            <h1 class="title">{{item.name}}</h1>
            <ul>
              <li class="food-item border-1px" v-for="food in item.foods">
                <div class="icon">
                  <img width="57" height="57" :src="imgUrl+food.image_path">
                </div>
                <div class="content">
                  <h2 class="name">{{food.name}}</h2>
                  <p class="desc">{{food.description}}</p>
                  <div class="extra">
                    <span class="count">{{food.tips}}<span style="margin-left: 20%;">好评率{{food.rating}}%</span></span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{food.specfoods[0].price}}</span>
                    <!--<span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>-->
                  </div>
                  <div class="cartcontrol-wrapper" >
                    <CartControl :food="food"/>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
    </div>
  </div>

</template>


<script>
  import BScroll from 'better-scroll'
  import CartControl from './CartControl'
  export default {
    components: {
      CartControl
    },
    data(){
          return{
            goods:'',
            tops:[],
            scrollY: 0,
           imgUrl: 'http://cangdu.org:8001/img/',
          }
    },
    computed:{
      currentIndex () {
          //返回的是当前的top是几 滑动到当前模块
        return this.tops.findIndex((top, index)=> {
          return this.scrollY>=top && this.scrollY<this.tops[index+1]
        })
      }

    },
    methods:{
      async msg(){
             var res = await this.$axios.get('http://cangdu.org:8001/shopping/v2/menu?restaurant_id=1')
             this.goods=res.data;
              console.log(this.goods)
               //来判断dom结构是否完全加载使用     this.$nextTick(() => {})
              this.$nextTick(() =>{
                this._initScroll();
                this._initTops();
              })
          },
      //初始化滚动插件better-scroll
      _initScroll () {
          //默认左侧是无点击事件的
        this.menuScroll = new BScroll(this.$refs.menuWrapper, {
          click: true
        })
        this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
          click: true,
          probeType: 3
        })
        //监视右侧li的滚动
        this.foodsScroll.on('scroll', (pos) => {
          this.scrollY = Math.abs(Math.round(pos.y))
        })
      },
      //实现左右联动并且实现文本的高亮
      _initTops () {
          //获取右侧dom  li
        const foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
        //初始的高度为0
        let top = 0;
        //添加到数组中
        this.tops.push(top)
        //遍历当前所有的li
        for(let i=0;i<foodList.length;i++){
          let item = foodList[i]
          top += item.clientHeight
          this.tops.push(top)
        }
        //获得的是高度
        console.log(this.tops)
      },
      //左侧点击功能
      clickMenuItem (index, event) {
        if(!event._constructed) {
          return
        }
        //运用BScroll接口，滚动到相应位置
        const foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
        //获取对应元素的列表
        const el = foodList[index]
        //设置滚动时间
        this.foodsScroll.scrollToElement(el, 300)
      }

    },
    mounted(){
          this.msg();
    }
  }
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../static/css/mixins.styl"
  .goods
    display: flex
    position: absolute
    top: 198px
    bottom: 46px
    width: 100%
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          color: $green
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat

        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          bottom-border-1px(rgba(7, 17, 27, 0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147, 153, 159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        bottom-border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7, 17, 27)
          .desc, .extra
            line-height: 10px
            font-size: 10px
            color: rgb(147, 153, 159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240, 20, 20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147, 153, 159)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>

